Are we talking impotent baby tablets like iPad or REAL tablet computers by the masters Fujitsu produced since the 90s? ... Ditto going back as far as the AMD 5x86 based machines...
Yes, tablets are nothing new, just changing form factors and increasing processing/memory. Besides the GRiDPad 1910 I mentioned before, which was the first ever commercial tablet, I have a couple even from IBM. Your Fujitsu tablets are popular, but my favorites are my Mitubishi Amitys - nice digital picture frames and photo albums to carry along.